mirror of
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0b24f9740f
Allow module parameters to be declared in the rust `module!` macro. Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> Tested-by: Daniel Gomez <da.gomez@samsung.com> Signed-off-by: Daniel Gomez <da.gomez@kernel.org>
538 lines
20 KiB
Rust
538 lines
20 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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use crate::helpers::*;
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use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
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use std::fmt::Write;
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fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> {
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let group = expect_group(it);
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assert_eq!(group.delimiter(), Delimiter::Bracket);
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let mut values = Vec::new();
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let mut it = group.stream().into_iter();
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while let Some(val) = try_string(&mut it) {
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assert!(val.is_ascii(), "Expected ASCII string");
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values.push(val);
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match it.next() {
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Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','),
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None => break,
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_ => panic!("Expected ',' or end of array"),
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}
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}
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values
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}
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struct ModInfoBuilder<'a> {
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module: &'a str,
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counter: usize,
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buffer: String,
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param_buffer: String,
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}
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impl<'a> ModInfoBuilder<'a> {
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fn new(module: &'a str) -> Self {
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ModInfoBuilder {
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module,
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counter: 0,
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buffer: String::new(),
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param_buffer: String::new(),
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}
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}
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fn emit_base(&mut self, field: &str, content: &str, builtin: bool, param: bool) {
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let string = if builtin {
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// Built-in modules prefix their modinfo strings by `module.`.
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format!(
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"{module}.{field}={content}\0",
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module = self.module,
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field = field,
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content = content
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)
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} else {
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// Loadable modules' modinfo strings go as-is.
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format!("{field}={content}\0")
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};
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let buffer = if param {
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&mut self.param_buffer
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} else {
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&mut self.buffer
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};
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write!(
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buffer,
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"
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{cfg}
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#[doc(hidden)]
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#[cfg_attr(not(target_os = \"macos\"), link_section = \".modinfo\")]
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#[used(compiler)]
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pub static __{module}_{counter}: [u8; {length}] = *{string};
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",
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cfg = if builtin {
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"#[cfg(not(MODULE))]"
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} else {
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"#[cfg(MODULE)]"
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},
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module = self.module.to_uppercase(),
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counter = self.counter,
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length = string.len(),
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string = Literal::byte_string(string.as_bytes()),
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)
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.unwrap();
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self.counter += 1;
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}
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fn emit_only_builtin(&mut self, field: &str, content: &str, param: bool) {
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self.emit_base(field, content, true, param)
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}
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fn emit_only_loadable(&mut self, field: &str, content: &str, param: bool) {
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self.emit_base(field, content, false, param)
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}
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fn emit(&mut self, field: &str, content: &str) {
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self.emit_internal(field, content, false);
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}
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fn emit_internal(&mut self, field: &str, content: &str, param: bool) {
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self.emit_only_builtin(field, content, param);
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self.emit_only_loadable(field, content, param);
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}
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fn emit_param(&mut self, field: &str, param: &str, content: &str) {
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let content = format!("{param}:{content}", param = param, content = content);
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self.emit_internal(field, &content, true);
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}
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fn emit_params(&mut self, info: &ModuleInfo) {
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let Some(params) = &info.params else {
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return;
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};
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for param in params {
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let ops = param_ops_path(¶m.ptype);
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// Note: The spelling of these fields is dictated by the user space
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// tool `modinfo`.
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self.emit_param("parmtype", ¶m.name, ¶m.ptype);
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self.emit_param("parm", ¶m.name, ¶m.description);
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write!(
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self.param_buffer,
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"
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pub(crate) static {param_name}:
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::kernel::module_param::ModuleParamAccess<{param_type}> =
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::kernel::module_param::ModuleParamAccess::new({param_default});
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const _: () = {{
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#[link_section = \"__param\"]
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#[used]
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static __{module_name}_{param_name}_struct:
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::kernel::module_param::KernelParam =
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::kernel::module_param::KernelParam::new(
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::kernel::bindings::kernel_param {{
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name: if ::core::cfg!(MODULE) {{
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::kernel::c_str!(\"{param_name}\").as_bytes_with_nul()
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}} else {{
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::kernel::c_str!(\"{module_name}.{param_name}\")
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.as_bytes_with_nul()
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}}.as_ptr(),
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// SAFETY: `__this_module` is constructed by the kernel at load
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// time and will not be freed until the module is unloaded.
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#[cfg(MODULE)]
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mod_: unsafe {{
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core::ptr::from_ref(&::kernel::bindings::__this_module)
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.cast_mut()
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}},
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#[cfg(not(MODULE))]
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mod_: ::core::ptr::null_mut(),
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ops: core::ptr::from_ref(&{ops}),
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perm: 0, // Will not appear in sysfs
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level: -1,
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flags: 0,
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__bindgen_anon_1: ::kernel::bindings::kernel_param__bindgen_ty_1 {{
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arg: {param_name}.as_void_ptr()
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}},
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}}
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);
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}};
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",
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module_name = info.name,
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param_type = param.ptype,
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param_default = param.default,
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param_name = param.name,
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ops = ops,
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)
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.unwrap();
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}
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}
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}
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fn param_ops_path(param_type: &str) -> &'static str {
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match param_type {
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"i8" => "::kernel::module_param::PARAM_OPS_I8",
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"u8" => "::kernel::module_param::PARAM_OPS_U8",
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"i16" => "::kernel::module_param::PARAM_OPS_I16",
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"u16" => "::kernel::module_param::PARAM_OPS_U16",
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"i32" => "::kernel::module_param::PARAM_OPS_I32",
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"u32" => "::kernel::module_param::PARAM_OPS_U32",
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"i64" => "::kernel::module_param::PARAM_OPS_I64",
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"u64" => "::kernel::module_param::PARAM_OPS_U64",
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"isize" => "::kernel::module_param::PARAM_OPS_ISIZE",
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"usize" => "::kernel::module_param::PARAM_OPS_USIZE",
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t => panic!("Unsupported parameter type {}", t),
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}
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}
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fn expect_param_default(param_it: &mut token_stream::IntoIter) -> String {
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assert_eq!(expect_ident(param_it), "default");
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assert_eq!(expect_punct(param_it), ':');
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let sign = try_sign(param_it);
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let default = try_literal(param_it).expect("Expected default param value");
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assert_eq!(expect_punct(param_it), ',');
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let mut value = sign.map(String::from).unwrap_or_default();
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value.push_str(&default);
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value
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}
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#[derive(Debug, Default)]
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struct ModuleInfo {
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type_: String,
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license: String,
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name: String,
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authors: Option<Vec<String>>,
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description: Option<String>,
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alias: Option<Vec<String>>,
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firmware: Option<Vec<String>>,
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params: Option<Vec<Parameter>>,
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}
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#[derive(Debug)]
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struct Parameter {
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name: String,
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ptype: String,
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default: String,
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description: String,
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}
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fn expect_params(it: &mut token_stream::IntoIter) -> Vec<Parameter> {
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let params = expect_group(it);
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assert_eq!(params.delimiter(), Delimiter::Brace);
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let mut it = params.stream().into_iter();
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let mut parsed = Vec::new();
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loop {
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let param_name = match it.next() {
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Some(TokenTree::Ident(ident)) => ident.to_string(),
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Some(_) => panic!("Expected Ident or end"),
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None => break,
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};
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assert_eq!(expect_punct(&mut it), ':');
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let param_type = expect_ident(&mut it);
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let group = expect_group(&mut it);
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assert_eq!(group.delimiter(), Delimiter::Brace);
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assert_eq!(expect_punct(&mut it), ',');
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let mut param_it = group.stream().into_iter();
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let param_default = expect_param_default(&mut param_it);
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let param_description = expect_string_field(&mut param_it, "description");
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expect_end(&mut param_it);
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parsed.push(Parameter {
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name: param_name,
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ptype: param_type,
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default: param_default,
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description: param_description,
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})
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}
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parsed
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}
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impl ModuleInfo {
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fn parse(it: &mut token_stream::IntoIter) -> Self {
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let mut info = ModuleInfo::default();
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const EXPECTED_KEYS: &[&str] = &[
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"type",
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"name",
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"authors",
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"description",
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"license",
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"alias",
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"firmware",
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"params",
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];
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const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
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let mut seen_keys = Vec::new();
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loop {
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let key = match it.next() {
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Some(TokenTree::Ident(ident)) => ident.to_string(),
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Some(_) => panic!("Expected Ident or end"),
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None => break,
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};
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if seen_keys.contains(&key) {
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panic!("Duplicated key \"{key}\". Keys can only be specified once.");
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}
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assert_eq!(expect_punct(it), ':');
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match key.as_str() {
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"type" => info.type_ = expect_ident(it),
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"name" => info.name = expect_string_ascii(it),
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"authors" => info.authors = Some(expect_string_array(it)),
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"description" => info.description = Some(expect_string(it)),
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"license" => info.license = expect_string_ascii(it),
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"alias" => info.alias = Some(expect_string_array(it)),
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"firmware" => info.firmware = Some(expect_string_array(it)),
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"params" => info.params = Some(expect_params(it)),
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_ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."),
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}
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assert_eq!(expect_punct(it), ',');
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seen_keys.push(key);
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}
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expect_end(it);
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for key in REQUIRED_KEYS {
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if !seen_keys.iter().any(|e| e == key) {
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panic!("Missing required key \"{key}\".");
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}
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}
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let mut ordered_keys: Vec<&str> = Vec::new();
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for key in EXPECTED_KEYS {
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if seen_keys.iter().any(|e| e == key) {
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ordered_keys.push(key);
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}
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}
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if seen_keys != ordered_keys {
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panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}.");
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}
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info
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}
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}
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pub(crate) fn module(ts: TokenStream) -> TokenStream {
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let mut it = ts.into_iter();
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let info = ModuleInfo::parse(&mut it);
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// Rust does not allow hyphens in identifiers, use underscore instead.
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let ident = info.name.replace('-', "_");
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let mut modinfo = ModInfoBuilder::new(ident.as_ref());
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if let Some(authors) = &info.authors {
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for author in authors {
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modinfo.emit("author", author);
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}
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}
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if let Some(description) = &info.description {
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modinfo.emit("description", description);
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}
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modinfo.emit("license", &info.license);
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if let Some(aliases) = &info.alias {
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for alias in aliases {
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modinfo.emit("alias", alias);
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}
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}
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if let Some(firmware) = &info.firmware {
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for fw in firmware {
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modinfo.emit("firmware", fw);
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}
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}
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// Built-in modules also export the `file` modinfo string.
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let file =
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std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
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modinfo.emit_only_builtin("file", &file, false);
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modinfo.emit_params(&info);
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format!(
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"
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/// The module name.
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///
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/// Used by the printing macros, e.g. [`info!`].
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const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
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// SAFETY: `__this_module` is constructed by the kernel at load time and will not be
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// freed until the module is unloaded.
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#[cfg(MODULE)]
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static THIS_MODULE: ::kernel::ThisModule = unsafe {{
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extern \"C\" {{
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static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
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}}
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::kernel::ThisModule::from_ptr(__this_module.get())
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}};
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#[cfg(not(MODULE))]
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static THIS_MODULE: ::kernel::ThisModule = unsafe {{
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::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
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}};
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/// The `LocalModule` type is the type of the module created by `module!`,
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/// `module_pci_driver!`, `module_platform_driver!`, etc.
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type LocalModule = {type_};
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impl ::kernel::ModuleMetadata for {type_} {{
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const NAME: &'static ::kernel::str::CStr = ::kernel::c_str!(\"{name}\");
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}}
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// Double nested modules, since then nobody can access the public items inside.
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mod __module_init {{
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mod __module_init {{
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use super::super::{type_};
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use pin_init::PinInit;
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/// The \"Rust loadable module\" mark.
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//
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// This may be best done another way later on, e.g. as a new modinfo
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// key or a new section. For the moment, keep it simple.
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#[cfg(MODULE)]
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#[doc(hidden)]
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#[used(compiler)]
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static __IS_RUST_MODULE: () = ();
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static mut __MOD: ::core::mem::MaybeUninit<{type_}> =
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::core::mem::MaybeUninit::uninit();
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// Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
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/// # Safety
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///
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/// This function must not be called after module initialization, because it may be
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/// freed after that completes.
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#[cfg(MODULE)]
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#[doc(hidden)]
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#[no_mangle]
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#[link_section = \".init.text\"]
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pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{
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// SAFETY: This function is inaccessible to the outside due to the double
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// module wrapping it. It is called exactly once by the C side via its
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// unique name.
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unsafe {{ __init() }}
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}}
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#[cfg(MODULE)]
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#[doc(hidden)]
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#[used(compiler)]
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#[link_section = \".init.data\"]
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static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;
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#[cfg(MODULE)]
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#[doc(hidden)]
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#[no_mangle]
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#[link_section = \".exit.text\"]
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pub extern \"C\" fn cleanup_module() {{
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// SAFETY:
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// - This function is inaccessible to the outside due to the double
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// module wrapping it. It is called exactly once by the C side via its
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// unique name,
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// - furthermore it is only called after `init_module` has returned `0`
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// (which delegates to `__init`).
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unsafe {{ __exit() }}
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}}
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#[cfg(MODULE)]
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#[doc(hidden)]
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#[used(compiler)]
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#[link_section = \".exit.data\"]
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static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;
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// Built-in modules are initialized through an initcall pointer
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// and the identifiers need to be unique.
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#[cfg(not(MODULE))]
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#[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
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#[doc(hidden)]
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#[link_section = \"{initcall_section}\"]
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#[used(compiler)]
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pub static __{ident}_initcall: extern \"C\" fn() ->
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::kernel::ffi::c_int = __{ident}_init;
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#[cfg(not(MODULE))]
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#[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
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::core::arch::global_asm!(
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r#\".section \"{initcall_section}\", \"a\"
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__{ident}_initcall:
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.long __{ident}_init - .
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.previous
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\"#
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);
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#[cfg(not(MODULE))]
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#[doc(hidden)]
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#[no_mangle]
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pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{
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// SAFETY: This function is inaccessible to the outside due to the double
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// module wrapping it. It is called exactly once by the C side via its
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// placement above in the initcall section.
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unsafe {{ __init() }}
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}}
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#[cfg(not(MODULE))]
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#[doc(hidden)]
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#[no_mangle]
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pub extern \"C\" fn __{ident}_exit() {{
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// SAFETY:
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// - This function is inaccessible to the outside due to the double
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// module wrapping it. It is called exactly once by the C side via its
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// unique name,
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// - furthermore it is only called after `__{ident}_init` has
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// returned `0` (which delegates to `__init`).
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unsafe {{ __exit() }}
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}}
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/// # Safety
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///
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/// This function must only be called once.
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unsafe fn __init() -> ::kernel::ffi::c_int {{
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let initer =
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<{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
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// SAFETY: No data race, since `__MOD` can only be accessed by this module
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// and there only `__init` and `__exit` access it. These functions are only
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// called once and `__exit` cannot be called before or during `__init`.
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match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{
|
|
Ok(m) => 0,
|
|
Err(e) => e.to_errno(),
|
|
}}
|
|
}}
|
|
|
|
/// # Safety
|
|
///
|
|
/// This function must
|
|
/// - only be called once,
|
|
/// - be called after `__init` has been called and returned `0`.
|
|
unsafe fn __exit() {{
|
|
// SAFETY: No data race, since `__MOD` can only be accessed by this module
|
|
// and there only `__init` and `__exit` access it. These functions are only
|
|
// called once and `__init` was already called.
|
|
unsafe {{
|
|
// Invokes `drop()` on `__MOD`, which should be used for cleanup.
|
|
__MOD.assume_init_drop();
|
|
}}
|
|
}}
|
|
{modinfo}
|
|
}}
|
|
}}
|
|
mod module_parameters {{
|
|
{params}
|
|
}}
|
|
",
|
|
type_ = info.type_,
|
|
name = info.name,
|
|
ident = ident,
|
|
modinfo = modinfo.buffer,
|
|
params = modinfo.param_buffer,
|
|
initcall_section = ".initcall6.init"
|
|
)
|
|
.parse()
|
|
.expect("Error parsing formatted string into token stream.")
|
|
}
|